Final answer:
A test that gives consistent scores across multiple administrations is considered to be reliable. Reliability is about the consistency of test results and is a crucial aspect of test development alongside validity, which ensures the test measures what it intends to measure. Standardization and avoidance of biased samples also contribute to test reliability.
Step-by-step explanation:
If a test yields close to the same score when taken by the same individual on different occasions, the test is said to be reliable. Reliability refers to the ability of a test to consistently produce a given result across multiple administrations. For example, if you were to take a personality test several times over a period of time, and each time the test resulted in the same or very similar outcomes, this test would be considered to have high test-retest reliability. In contrast to validity, which is the extent to which a test measures what it is supposed to measure, reliability is solely about the consistency of the test results. A reliable test is not necessarily valid, but a valid test must be reliable.
It is essential for a test to be standardized, meaning it is administered, scored, and interpreted in a consistent and standard manner across all test-takers to be reliable. Problems such as a biased sample can affect the reliability of a test. A representative sample is necessary to ensure that a test is both reliable and valid, as it must reflect the population the test is intended to measure.